The study, which included more than 3,000 veterans at 13 VA medical centers, provides the most concrete evidence yet that vitamin D--the "sunshine vitamin--may play a role in the prevention of colorectal cancer.
"The finding that may surprise the scientific community is the vitamin D data," said lead investigator David Lieberman, MD, chief of gastroenterology at the Portland VA Medical Center and Oregon Health and Science University. " Higher levels of Vitamin D intake were associated with a lower risk of serious colon polyps. There have been some studies suggesting this, but our data are compelling."
In the study, men who consumed higher amounts of cereal fiber--more than about 4 grams per day--and vitamin D--more than 645 international units (IUs) per day--were significantly less likely to have serious colon polyps, or tumors, which are often the precursor to cancer. Another significant association with reduced risk was the use of non-steroidal anti-inflammatory drugs:
Men who took a daily aspirin were about two-thirds as likely to have a tumor. Lieberman said further study is needed before recommending this solely for protection against colon tumors, due to the potential for side effects over a lifetime of anti-inflammatory consumption. Exercise, calcium, folic acid and multivitamins were shown in the study to be marginally beneficial in lowering risk.
In looking at factors that increase the risk of colon cancer, the research poses yet another reason to quit smoking: Smoking increased by nearly twofold the risk of hav
Contact: Patricia Forsyth
VA Research Communications Service